Wrapped up in a dark coat, balaclava and sunglasses, Irene Williams cuts an unusual figure as she visits her local supermarket to do her weekly shop.

But her strange choice of attire is not meant to hide her face, masking her identity.

Rather it is designed to protect the 58-year-old, who must live in the dark for a month, while she trials a new drug to treat her cancer.

Mrs Williams is the first patient to take part in the international trial of the drug Amphinex, which, it is hoped, will be used to treat patients with inoperable bile duct cancer.

Irene Williams, 38, may look like a robber but actually her balaclava and sunglasses are because she is taking part in a trial of new drug Amphinex. Amphinex is reactive to light, and could be used to treat patients with inoperable bile duct cancer

She was given the drug by doctors at Aintree University Hospital in Liverpool, which is the first in the world to trial Amphinex.

The drug, which enters into the cancerous cells themselves, is taken alongside chemotherapy.

It reacts to light so doctors warned she had to stay in hospital for two weeks before going home. They said she had to cover her body completely when going outdoors.

It prompted the 58-year-old to opt for sunglasses and a balaclava, as well as a pair of gloves, when she steps outside.

‘I went to my local hospital in Wales for a scan and they initially told me it was a gall bladder stone’ she said.

However, at a follow-up appointment, she was told that the situation was more serious.

She was referred to a hospital in Liverpool and was diagnosed with bile duct cancer after two weeks of tests.

Following her diagnosis, Ms Williams met with Dr Richard Sturgess, clinical director of digestive diseases at Aintree University Hospital in Liverpool, who told her about the Amphinex trial.

She felt the drug might help and wanted to take part.

She said: ‘I wanted to get involved straight away. I had nothing to lose and so much to gain.

'I have four sisters and a brother in Liverpool and they were all supportive.’

Before beginning her chemotherapy treatment, which she receives three times a month at the Clatterbridge Cancer Centre in Wirral, she had had Amphinex injected into her system and ‘activated’ at Aintree University Hospital in Liverpool.

Amphinex works by entering cancerous cells within tumours. It is then ‘activated’ by inserting a laser into the bile duct, which illuminates the area where the bile duct cancer occurs.

Doctors hope this will enhance the effects of traditional chemotherapy by targeting individual tumours rather than treating the patient’s whole body.

Amphinex, which is produced by Norwegian company PCI Biotech, is already used in the treatment of some other cancers but has never been used to treat bile duct cancer before.

Care assistant Ms Williams, who lives in Llandudno in north Wales, was diagnosed with bile duct cancer in November after she noticed she was turning yellow and was suffering a bout of vomitting

The study involves hospitals across Europe but Aintree University Hospital is the lead site.

Dr Sturgess, who referred Ms Williams for the Amphinex trial said: ‘I’m delighted that our patients have had the opportunity to benefit from this research study. As a hospital, we are committed to cutting-edge research.

‘Bile duct cancer is a devastating disease with a very clear need of better, alternative treatments.

'It has a remarkable resistance to conventional treatment and this trial represents an innovative concept that could potentially improve the length and quality of life for patients.’